Concrete screeding machine with improved auger

ABSTRACT

A screeding machine for screeding a concrete surface having a partially cured concrete area and a newly placed concrete area includes a wheeled unit and a screeding head attached at the wheeled unit. The wheeled unit has a plurality of wheels for moving the wheeled unit over a support surface. The screeding head assembly includes a grade setting device and a vibrating member and is movable over the concrete area via the wheeled unit. The grade setting device includes an auger device having a longitudinal body and at least one flighting helically disposed around and along the body. The spacings between respective longitudinally adjacent vane portions of the at least one flighting vary longitudinally along the auger device.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims the filing benefits of U.S. provisionalapplication Ser. No. 61/806,672, filed Mar. 29, 2013, which is herebyincorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates generally to an apparatus and method forimproving the control and productivity of a concrete screeding machineduring the leveling and smoothing of freshly poured concrete that hasbeen placed over a surface.

BACKGROUND OF THE INVENTION

Screeding devices or machines are used to level and smooth uncuredconcrete to a desired grade. Known screeding machines typically includea screed head, which includes a vibrating member and a grade settingdevice, such as a plow or auger device. The screed head is verticallyadjustable, such as in response to a laser leveling system, to establishthe desired grade at the vibrating member. Examples of such screedingmachines are described in U.S. Pat. Nos. 4,655,633; 4,930,935;6,227,761; 7,044,681; 7,175,363; and 7,396,186, which are herebyincorporated herein by reference in their entireties.

SUMMARY OF THE INVENTION

The present invention provides a screeding machine that comprises ascreed head having a vibrating member and a grade setting device. Thegrade setting device comprises an auger device that has at least twoseparate spiral or helical flightings disposed on and around and atleast partially along a rotatable shaft or body of the auger. Thehelical flightings are staged or configured or arranged so that at leasta portion of the auger has a first flighting portion or region having afirst longitudinal spacing between adjacent fins or vanes of the helicalflighting or flightings and a second flighting portion or region havinga second longitudinal spacing between adjacent fins or vanes of thehelical flighting or flightings.

According to an aspect of the present invention, an auger may have threeseparate and distinct flightings or vanes that are helically disposedalong a rotatable shaft or body of the auger. A first one of theflightings may be helically disposed substantially along the entirelength of the body, while a second one of the flightings may behelically disposed along a shorter length of the body, such as, forexample, along about two-thirds of the length of the body that isencompassed by the first flighting, with the second flighting beingspaced from the first flighting. Optionally, a third flighting may behelically disposed along a shorter length of the body, such as, forexample, along about one-third of the length of the body that isencompassed by the first flighting (and thus, for example, about half ofthe length of the body that is encompassed by the second flighting),with the second flighting being spaced from the first and secondflightings. In such a configuration, the spacing between the first,second and third flightings may be substantially uniform (i.e., thelongitudinal spacing between the first flighting and second flighting isthe same as the longitudinal spacing between the second flighting andthe third flighting, and is the same as the longitudinal spacing betweenthe third flighting and the first flighting.

Optionally, the longitudinal spacing along the body between adjacentportions of the flightings may be uniform along the body. Thus, thesecond flighting may only extend partially along a middle region (suchas, for example, a middle third) of the body and may be disposed mid-waybetween the adjacent flighting portions of the first flighting. At athird portion of the body, the second flighting may terminate and athird and fourth flighting may be disposed equally spaced from oneanother and from the first flighting to provide three flightings at thethird portion of the body.

Thus, the present invention provides a staged flighting auger devicethat has different flighting configurations along its length. Forexample, at one end or portion of the auger (such as a downstreamportion or region or discharge end of the auger), the auger may have atighter or closer configuration of flightings or vanes, and at anotherend or portion of the auger (such as an upstream portion or region orend of the auger), the auger may have a more spaced apart configurationof flightings or vanes. The denser configuration is at the downstreamend of the auger with the more spaced flighting configuration being atthe upstream end of the auger, such that, as more concrete is moved bythe auger and the concrete starts to build up as it is moved by theauger, the denser spacing flighting configuration enhances movement ofthe larger volume of concrete.

These and other objects, advantages, purposes and features of thepresent invention will become apparent upon review of the followingspecification in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a concrete leveling and screedingmachine that incorporates the improved operator controls and controlsystems and screed head apparatus design improvements and features ofthe present invention;

FIG. 2 is a perspective view of an auger having staged flighting inaccordance with the present invention;

FIG. 3 is a perspective view of another auger having staged flighting inaccordance with the present invention;

FIG. 4 is another perspective view of the auger of FIG. 3;

FIG. 5 is a perspective view of another auger having staged flighting inaccordance with the present invention;

FIGS. 6-9 are plan views of the auger of FIG. 5;

FIG. 10 is a perspective view of an end region of an auger of thepresent invention, showing an internal bearing mount for mounting theauger at the screed head in accordance with the present invention;

FIG. 11 is another perspective view of the auger of FIG. 10, showing theauger mounted at an auger support beam of the screed head;

FIG. 12 is a sectional view of the end region of the auger of FIG. 10;

FIG. 12A is an enlarged sectional view of the area A in FIG. 12; and

FIG. 13 is a perspective view and partial sectional view of the augerand internal bearing mount of FIGS. 10 and 11, shown with the augermounted at the auger support beam.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings and the illustrative embodiments depictedtherein, a screeding machine 10 includes a wheeled unit 12 with a boom14 extending therefrom and supporting a screeding head or assembly 16 atan outer end thereof (FIG. 1). The wheeled unit 12 is drivable to atargeted area at a support surface with uncured concrete placed thereat,and the wheeled unit may rotate about a base portion to swing the boomand screeding head to a targeted location. The boom 14 is extendable andretractable to move the screeding head 16 over the placed concrete,while the screeding head 16 is operable to establish a desired grade ofthe concrete surface and smooth or finish or screed the concrete. In theillustrated embodiment, the screeding head includes a plow 18, a gradesetting device or auger 20 and a vibrating member 22 (FIG. 3). Thescreeding machine includes a plurality of stabilizers 24 that areextendable and retractable to support and stabilize the machine on thesupport surface during the screeding operation. The auger 20 ofscreeding head 16 comprises a staged flighting or vane configurationwith multiple spiral or helical flightings or vanes staged along theauger, such that the auger has a coarser or less dense or more spaceddistribution at or near the upstream end of the auger and a denserdistribution or configuration of vanes at the downstream or dischargeend or region of the auger, so that the auger of the present inventionhas improved or enhanced efficiency and provides enhanced movement ofconcrete to the discharge end of the auger, as discussed below.

Screeding machine 10 and the screeding head or assembly 16 may besimilar in construction and/or operation as the screeding machines andscreeding heads described in U.S. Pat. Nos. 4,655,633; 4,930,935;6,227,761; 7,044,681; 7,175,363; and/or 7,396,186, and/or U.S.Publication Nos. US-2007-0116520 and/or US-2010-0196096, which are allhereby incorporated herein by reference in their entireties, such that adetailed discussion of the overall construction and operation of thescreeding machines and screeding heads need not be repeated herein. Forexample, the screeding machine may comprise or may utilize aspects of aSomero SXP-D LASER SCREED™ screeding machine. However, clearly thisexample is not intended to limit the scope of the present applicationand clearly aspects of the present invention are suitable for use onother types of screeding machines. For example, the screeding head andauger device of the present invention may be suitable for use on asmaller screeding machine, such as a machine of the types described inU.S. Pat. Nos. 6,976,805; 7,121,762; and/or 7,850,396, which are herebyincorporated herein by reference in their entireties. Optionally,although shown in FIG. 1 as having a plow 18, the screed head may notinclude a plow, whereby the auger establishes the desired grade ofconcrete ahead of the vibrating member.

As shown in FIG. 2, auger 20 comprises a mounting shaft 24, whichprotrudes from a generally cylindrical body or shaft 26, which hasflightings or vanes 28 spirally or helically disposed therearound andtherealong. The auger has an upstream end or region 20 a, where theflightings may be more coarsely or less densely distributed or spaced,and a downstream end or region 20 b, where the flighting or flightingsmay be more densely distributed or spaced. In the illustrated embodimentof FIG. 2, flightings 28 comprise a first helical flighting or vane 30that is disposed helically around the body 26 and along a first portionof the body 26 (such as substantially the entire length of the body). Asecond helical flighting or vane 32 is disposed helically around thebody 26 and along a second portion of the body (such as, for example,about two-thirds of the length of the body), with the second portionbeing a reduced amount of the first portion. A third helical flightingor vane 34 is disposed helically around the body 26 and along a thirdportion of the body (such as, for example, about one-third of the lengthof the body), with the third portion being a reduced amount of thesecond portion.

Thus, the first portion of the body 26 has a coarse or spaced apartdistribution of the flighting therealong, while the second portion ofthe body has a reduced spacing or distribution of the flightingtherealong and the third portion of the body has a further reducedspacing of the flighting therealong. In the illustrated embodiment ofFIG. 2, at the second body portion (such as a middle third of the body),the second flighting is spaced from the first flighting at aboutone-third of the way between the corresponding portions of the firstflighting (so that the second flighting is not centered between thefirst flighting portions. The third flighting is then disposed at amiddle region between the second and first flighting so that, at thethird portion of the body, the three flightings 30, 32, 34 are spacedequidistantly along the body.

In the illustrated embodiment of FIG. 2, the flightings 30, 32, 34 havethe same pitch and thus are disposed generally parallel to one anotheralong the respective portions of the body 26. For example, the auger maycomprise a nine inch diameter auger with the flighting having a pitch ofabout nine inches per revolution. The first flighting 30 extendscontinuously and helically around and along the body, while the secondflighting 32 starts at a start portion 32 a (that may be about one-thirdof the length of the body from the upstream end 20 a of the auger) andextends continuously and helically around and along the body from itsstart portion 32 a to the downstream or discharge end 20 b of the auger,and the third flighting 34 starts at a start portion 34 a (that may beabout two-thirds of the length of the body from the upstream end 20 a ofthe auger) and extends continuously and helically around and along thebody from its start portion 34 a to the downstream or discharge end 20 bof the auger. The auger thus provides a finer or reduced spacingdistribution of flightings or vanes at the downstream or discharge endof the auger as compared to a middle region of the auger, which providesa finer or reduced spacing distribution of flightings or vanes at themiddle region of the auger as compared to the upstream region of theauger (where a coarser or greater spacing between the flighting isprovided).

Optionally, the auger of the present invention may have discontinuousflightings or flighting portions therealong, so that the flightings arespaced equidistant apart along each portion or region of the auger orbody. For example, and with reference to FIGS. 3 and 4, an auger 20′comprises a body 26′ with staged flightings 28′ disposed therealong. Inthe illustrated embodiment, the first helical flighting or vane 30′ isdisposed helically around the body 26 and along a first portion of thebody 26 (such as substantially the entire length of the body), while asecond helical flighting or vane 32′ is disposed helically around thebody 26 and along a second portion of the body (such as, for example,about a middle one-third portion of the body), with the second flighting32′ starting at an end 32 a′ (that is about one-third of the length ofthe body from the upstream end 20 a′ of the auger) and ending at an end32 b′ (that is about two-thirds of the length of the body from theupstream end 20 a′ of the auger). At the third portion or region (thedownstream region) of the body and auger, a third flighting 34′ and afourth flighting 33′ are disposed helically around the body 26′ andalong the third portion of the body (such as, for example, aboutone-third of the length of the body at the downstream or discharge endof the auger). As shown in FIG. 3, the second flighting 32′ is disposedmidway between the first flighting 30′ so that the vanes or flightingshave equidistant spacing or uniform spacing along the second or middleregion of the auger, while the third and fourth flightings 34′, 33′ aredisposed equidistant from one another and from the first flighting 30′at the third or downstream portion or region of the auger, so theflightings have equidistant spacing or uniform spacing along the thirdor downstream region of the auger. The ends of the respective flightings30′, 32′, 33′, 34′ may comprise angled or tapered ends (such as end 32a′ in FIG. 3) or may be squared or sharp cut ends (such as the end 32 a″in FIG. 4), without affecting the scope of the present invention.

Optionally, and with reference to FIGS. 5-9, an auger 20″ may haveflightings 28′ along the body 26′ similar to auger 20′, discussed above,with a transitional flighting or vane element 36″ established betweenthe end 32 b′ of the second flighting 32′ and the start or end 33 a′ ofthe fourth flighting 33′. As can also be seen in FIGS. 5-9, the thirdflighting 34′ starts at 34 a′ at or near where the transitional element36″ is disposed. In the illustrated embodiment, for example, the auger20″ comprises a nine inch diameter auger and all four flightings 30′,32′, 34′, 33′ have a pitch or lead of nine inches per revolution, withthe exception of the transitional section or element 36″. Thetransitional section or element 36″ in this example has a pitch of about15 inches per revolution and is only about one quarter of a revolutionin effective length, thus smoothly and continuously joining the secondflighting 32′ with the fourth flighting 33′ to provide a continuousflighting over the upstream two-thirds of the auger. The transitionalsection or element 36″ thus allows for an auger with equal spacing ofthe flightings along the auger (such as about nine inches between theflights of the first flighting, and about 4.5 inches between the flightsof the first and second flightings, and about three inches between theflights of the first and fourth flightings and the fourth and thirdflightings and third and first flightings).

Thus, the staged flighting or variable flighting arrangement orconfiguration of the auger of the present invention provides a coarseror larger spacing of flights or vanes at or near an upstream end of theauger and a finer or closer spacing of flights or vanes at or near adownstream or discharge end of the auger. Thus, during operation of theauger, as the auger is rotated while engaging the concrete surface andexcess concrete at the desired grade (with the auger being rotatablydriven, such as via a hydraulic motor or the like at an end of theauger, in a direction opposite to the direction of travel of the screedhead assembly), the coarser spacing of the upstream end flightings maystart to move concrete along the auger and towards the discharge end ofthe auger. As the concrete accumulates as it moves along the auger, thespacing between the flightings decreases to enhance movement of theadditional concrete moved along the auger from the upstream end, and thespacing between the flightings decreases more at or near the dischargeend of the auger to further accommodate accumulated concrete and enhancemovement of the concrete at or near the discharge end of the auger.

Although shown and described as an auger having three distinct portionsor regions with different flighting spacings or gaps, clearly more orless portions may be provided along the auger while remaining within thespirit and scope of the present invention. For example, an auger mayonly have two flighting sections, with an upstream half of the auger (orother portion or fraction of the auger) having a single flightingarrangement and the downstream half of the auger (or other portion orfraction of the auger) having a dual flighting arrangement. Optionally,for example, an auger may have four or more flighting sections, such aswith a single flighting extending the full length of the auger, a secondflighting extending about three quarters of the length of the auger, athird flighting extending about half of the length of the auger and afourth flighting extending about one quarter of the length of the auger.The flightings may be uniformly spaced or the spacing may only beuniform at the first and fourth quarters, and the auger may includetransitional sections to join different flighting sections together,such as discussed above, while remaining within the spirit and scope ofthe present invention. Optionally, the auger may have one or moreflightings extending substantially along the length of the auger, withthe pitch of the flightings varying from a coarser or larger pitch at ornear the upstream end of the auger to a finer or smaller pitch at ornear the downstream or discharge end of the auger.

Thus, the present invention provides a staged or varying flightingauger, which provides an increased concrete carrying capacity as excessconcrete increasingly accumulates toward the discharge end of the auger.The auger of the present invention may also provide a reduced augerweight from “all full length flights”, because the flights or flightingsare added along the direction of concrete flow and movement where theyare most needed. The weight of extra flighting is eliminated at theupstream end (in other words, at the starting end of the auger, whereoverlap normally occurs over the previous pass).

The present invention may also provide for reduced auger flighting wearat the discharge end of the auger. Current augers typically need to beflipped end-to-end to maximize useful life due to uneven wear. Thepresent invention avoids this and thus provides a machine-operatormaintenance benefit.

The preferred multiple, staged flighting configuration of the presentinvention provides a uniform and substantially constant pitch (such asabout 9 inches or thereabouts) along the auger. Optionally, the auger ofthe present invention may provide one or more flightings with a varyingpitch of the flighting or flightings along the auger. However, a varyingpitch (having a smaller or reduced pitch at or near the discharge end ofthe auger to provide a denser or closer spacing arrangement of theflighting at or near the discharge end of the auger) may slow down thelateral velocity of the concrete as the flights or vanes get closertogether and the concrete moves towards and reaches the end of theauger. The multi-flight staged configurations of the present inventionpreferably provide equal pitch flighting that provides enhanced concretemovement.

The auger may be mounted at the screed head via any suitable mountingmeans. Optionally, the auger may be mounted at the screed head via aninternal bearing mounting assembly, which rotatably mounts the augerbody to a fixed shaft via an internal bearing that is received in theend of the hollow auger body. For example, and with reference to FIGS.10-13, an auger 120 (such as any of the staged flighting augersdiscussed above or a conventional single flighting auger or the like)includes a cylindrical body portion 126 with flighting 128 helicallydisposed therealong. At an end of the auger, such as at the downstreamor discharge end of the auger in FIGS. 10-13, an auger mounting assembly140 is disposed to rotatably mount the respective end of the auger at anauger support beam or element 142 of the screed head 116. The augermounting assembly comprises a stationary or fixed shaft 144 thatprotrudes from a bolt on end cap or attachment plate 146, with amounting bracket or structural support 148 attached to and extendingradially outwardly and upwardly from the fixed shaft 144 for attachingat the auger support beam 142 (as shown in FIGS. 11 and 13).

As best shown in FIGS. 12 and 13, auger mounting assembly 140 includesan internal bearing 150, with a race 150 a fixedly attached or locked tothe fixed shaft 144, and with an outer bearing surface rotatably engagedwith an inner sleeve 152 that is inserted into or received in the hollowend of the body 126, such as via an outer race 150 b of the bearingassembly 150. In the illustrated embodiment, a lubrication port orgrease fitting 154 is provided at the bearing assembly 150 and insidethe body and inboard of the end cap 146, which is bolted or fastened orattached to the inner sleeve 152 to attach the end cap 146 at the body126 and seal or enclose the bearings within the auger body. The end capmay be removed to access the grease fitting 154 as desired.

Thus, the mounting assembly 140 of the present invention provides asealed bearing within the auger body. The sleeve 152 is inserted intothe auger body and may be press fit or welded thereto to fixedly attachthe sleeve to the body. In the illustrated embodiment, the sleeveincludes a raised shoulder 152 a at its outboard end to limit insertionof the sleeve into the body, and the raised shoulder portion may have anouter surface that is generally flush with the outer surface of thebody, whereby the flighting 128 may extend over the outer surface of theraised shoulder portion of the sleeve (such as shown in FIGS. 10-13).The bearing assembly (with the fixed shaft attached thereto) is insertedinto the sleeve and the end cap 146 is attached or fastened to thesleeve to retain and seal the bearing within the sleeve 152 and augerbody 126.

The potential benefits of the internal bearing mount of the presentinvention include that the relatively thin vertical structural supportand relatively reduced diameter of the stationary shaft at the dischargeend of the auger offers less resistance to the movement of concrete awayfrom the end of the auger. Known current pillow-block type bearings aremounted externally at the rotating shafts of current augers and tend tohave a higher cross-sectional area than what is provided by the internalbearing mount of the present invention. Also, with the bearing mountedinternally inside the auger body or tube, there is reduced exposure toconcrete and stone aggregate at the bearings. Current designs typicallyrequire a plastic collar on the shaft between the bearing and the end ofthe auger to help prevent stones from jamming between the rotating partsand destroying the grease seals of the bearings. The internal bearingmount of the present invention may also allow a shaft seal to beincluded between the stationary shaft and rotating end cap of the auger(not currently shown), further protecting the actual grease seals of thebearing itself. Also, exposure to pressure washing of the screed head atthe end of the day by machine operators tends to reduce the life ofbearings whenever water gets inside the bearings. The bearings need tobe greased to help force out any water after pressure washing iscomplete. However, the internal bearing mount of the present inventionmay help reduce the likelihood of failures from water contamination.Optionally, the internal bearing mount of the present invention mayinclude a type of access port with a sealed, yet removable, access coverat the grease fitting to ease the greasing when greasing may be desiredor necessary.

The opposite end of the auger (such as the upstream end of the auger)may be mounted via any known mounting means and may be rotatably drivenvia a hydraulic motor and known pillow-block bearing supporting theauger (not shown). However, optionally, the auger motor may be mountedinternally inside the auger itself. In such a configuration, the shaftof the auger motor may remain stationary with the flow of pressurizedhydraulic fluid traveling through ports and internal passageways of thestationary motor shaft.

Changes and modifications to the specifically described embodiments canbe carried out without departing from the principles of the presentinvention, which is intended to be limited only by the scope of theappended claims as interpreted according to the principles of patentlaw.

1. A screeding machine for screeding a concrete surface having apartially cured concrete area and a newly placed concrete area, saidscreeding machine comprising: a wheeled unit having a plurality ofwheels for moving said wheeled unit over a support surface; a screedinghead assembly having a grade setting device and a vibrating member,wherein said screeding head assembly is movable over the concrete areavia said wheeled unit; wherein said grade setting device comprises anauger device having a longitudinal body and at least one flightinghelically disposed around and along said body; and wherein the spacingsbetween respective longitudinally adjacent vane portions of said atleast one flighting vary longitudinally along said auger device.
 2. Thescreeding machine of claim 1, wherein said at least one flightingcomprises first and second flightings.
 3. The screeding machine of claim2, wherein said first flighting is helically disposed along a firstportion of said body and said second flighting is helically disposedalong a second portion of said body, and wherein said second portion ofsaid body is a smaller portion of said first portion and wherein saidfirst portion of said body encompasses said second portion of said body.4. The screeding machine of claim 3, wherein said second flighting iscentrally disposed between vane portions of said first flighting so thatsaid first and second flightings are uniformly spaced apart along saidsecond portion of said body.
 5. The screeding machine of claim 3,wherein said second flighting is disposed between vane portions of saidfirst flighting so that said first and second flightings arenon-uniformly spaced apart along said second portion of said body. 6.The screeding machine of claim 3, wherein said at least one flightingcomprises a third flighting helically disposed along a third portion ofsaid body, and wherein said third portion of said body is a smallerportion of said second portion and wherein said second portion of saidbody encompasses said third portion of said body.
 7. The screedingmachine of claim 6, wherein said first, second and third flightings areuniformly spaced apart along said third portion of said body.
 8. Thescreeding machine of claim 7, wherein said second flighting comprises acontinuous flighting having a constant pitch along said second portionof said body.
 9. The screeding machine of claim 7, wherein said secondflighting comprises a central flighting portion at a central portion ofsaid body and an end flighting portion at said third portion of saidbody, and wherein said central flighting portion of said secondflighting and said first flighting are uniformly spaced apart along saidcentral portion of said body, and wherein said end flighting portion ofsaid second flighting, said third flighting and said first flighting areuniformly spaced apart along said third portion of said body.
 10. Thescreeding machine of claim 9, comprising a transition flighting elementdisposed between said central flighting portion of said second flightingand said end flighting portion of said second flighting, wherein saidtransition flighting element has a different pitch than said centralflighting portion and said end flighting portion and joins said centralflighting portion to said end flighting portion to provide asubstantially continuous second flighting along said second bodyportion.
 11. The screeding machine of claim 1, wherein said at least oneflighting comprises a continuous flighting having a varying pitch, witha greater pitch at an upstream region of said auger device and a reducedpitch at a downstream region of said auger device.
 12. The screedingmachine of claim 1, wherein said auger device is mounted at saidscreeding head via an internal bearing mounting assembly.
 13. Thescreeding machine of claim 1, wherein said screeding head assembly ismovable over the concrete area via an extendable and retractable boomassembly extending from said wheeled unit.
 14. The screeding machine ofclaim 1, wherein said screeding head assembly is movable via a wheeledunit that moves through the uncured concrete with said screeding headassembly following said wheeled unit.
 15. A screeding head assembly fora screeding machine for screeding a concrete surface having a partiallycured concrete area and a newly placed concrete area, said screedinghead assembly comprising: a grade setting device; a vibrating member;wherein said screeding head assembly is configured to be movable overthe concrete area via said screeding machine to establish the grade andscreed uncured concrete at the concrete area; wherein said grade settingdevice comprises an auger device having a longitudinal body and at leastone flighting helically disposed around and along said body; and whereinthe spacings between respective longitudinally adjacent vane portions ofsaid at least one flighting vary longitudinally along said auger device.16. The screeding head assembly of claim 15, wherein said at least oneflighting comprises a first flighting and a second flighting helicallydisposed around and along said body, and wherein said first flighting ishelically disposed along a first portion of said body and said secondflighting is helically disposed along a second portion of said body, andwherein said second portion of said body is a smaller portion of saidfirst portion and wherein said first portion of said body encompassessaid second portion of said body.
 17. The screeding head assembly ofclaim 16, wherein said second flighting is centrally disposed betweenvane portions of said first flighting so that said first and secondflightings are uniformly spaced apart along said second portion of saidbody.
 18. The screeding head assembly of claim 16, wherein said secondflighting is disposed between vane portions of said first flighting sothat said first and second flightings are non-uniformly spaced apartalong said second portion of said body.
 19. The screeding head assemblyof claim 16, comprising a third flighting helically disposed along athird portion of said body, and wherein said third portion of said bodyis a smaller portion of said second portion and wherein said secondportion of said body encompasses said third portion of said body. 20.The screeding head assembly of claim 15, wherein said at least oneflighting comprises a continuous flighting having a varying pitch, witha greater pitch at an upstream region of said auger device and a reducedpitch at a downstream region of said auger device.